Regorafenib is chemically known as 4-[4-({[4-chloro-3-(trifluoromethyl)phenyl]carbamoyl}amino)-3-fluorophenoxy]-N-methylpyridine-2-carboxamide and has the structural formula:

Regorafenib (BAY 73-4506) is an oral multi-kinase inhibitor which targets angiogenic, stromal and oncogenic receptor tyrosine kinase (RTK). Regorafenib shows anti-angiogenic activity due to its dual targeted VEGFR2-TIE2 tyrosine kinase inhibition. It is currently being studied as a potential treatment option in multiple tumor types. The generic name Regorafenib is marketed by BAYER HEALTHCARE under the brand name STIVARGA®.
Regorafenib as a compound is disclosed in U.S. Pat. No. 8,637,553. This patent application also discloses a process for the preparation of Regorafenib, which is as shown below:
4-Amino-3-fluorophenol and 4-chloro-N- methyl-2-pyridinecarboxamide was condensed in the presence of potassium tert-butoxide, N,N-dimethylacetamide to form 4-(4-amino-3-fluorophenoxy)pyridine-2-carboxylic acid methylamide as a reddish brown solid and thereafter condensed with 4-chloro-3-(trifluoromethyl)phenyl isocyanate in toluene to form 4{4-[3-(4-chloro-3-trifluoromethylphenyl)-ureido]-3-fluorophenoxy}-pyridine-2-carboxylic acid methylamide (Regorafenib) as residue, which was triturated with diethyl ether and dried for 4 h under vacuum to obtain Regorafenib. However, the present inventors have observed that the obtained Regorafenib compound is not pure and further the trituration or column chromatography is not useful for industrial scale production.
WO 2008/043446 discloses Regorafenib polymorphic I, which is stated as obtained by following the process described in WO 2005/009961. Further this patent application also discloses monohydrate Form of Regorafenib, which is prepared by dissolving Regorafenib polymorph I in acetone or ethanol or acetonitrile or tetrahydrofuran and adding water as antisolvent.
WO 2008/055629 discloses Polymorph III of Regorafenib, which is prepared by heating Regorafenib monohydrate.
WO 2008/058644 discloses Polymorph II of Regorafenib, which is prepared by suspending Regorafenib Polymorph I in ethyl acetate by heating and thereafter cooling.
In the prior-art there is no exemplified process or described process for preparing Regorafenib polymorph I, having high purity, industrially applicable and commercially viable. The present inventors have now found a process for the preparation of Regorafenib polymorph Form I, which is industrially viable.